Cyclopropylcarbinyl amine

An n.m.r. spectrum of cyclobutylamine in carbon tetrachloride showed no resonance signals at less than 1 p.p.m. from tetramethylsilane. This suggests that no cyclopropylcarbinyl-amine was formed by rearrangement during the reaction. 

Solvolytic studies provided the first structural indication for almost every carbocation-ic intermediate and the C4H,+ ion is no exception. Roberts observed that the solvolysis of cyclopropylcarbinyl or cyclobutyl systems and the diazotative deamination reactions of cyclopropylcarbinyl amine or cyclobutyl amine gave similar product mixtures consisting of cyclopropylcarbinyl, cyclobutyl and allylcarbinyl derivatives in essentially the same ratio1,2. A common cationic intermediate of C3v structure, the tricyclobutonium ion 1, was... 

When cyclopropylcarbinyl amine labeled with 14C in the 4-position is deaminated, the label is found to be scrambled in the products so that the three methylene groups have almost—but not quite—achieved equivalence. The... 

Roberts suggested that a set of charge-delocalized, rapidly equilibrating carbonium ions, which he called bicyclobutotiium ions, areThe first-formed ions from all three systems, In Scheme 3 are shown the bicvclobntnninm inns fm-mad fmm the deamination of 14C-labeled cyclopropylcarbinyl amine (Equation 6.32). According to Roberts, there would be two equivalent first-formed rarhonium... 

In 1951 Roberts observed that most cationic reactions of cyclopropylcarbinyl and of cyclobutyl derivatives give the same products in nearly the same ratio.73 For example, cyclopropylcarbinyl and cyclobutyl amines on deamination form the products shown in Equation 6.31.74 Moreover, when allylcarbinyl tosylate (63)... 

A wide range of alkenes may be used as substrates. The reaction is most commonly performed with alkenes of normal electronic nature, but electron deficient alkenes, such as a, 3-unsaturated carbonyl compounds, and very electron rich alkenes, such as enol ethers and enamines, have also been used successfully. Not surprisingly, the cyclopropylcarbinyl ethers and amines that are formed in the latter reactions (see Table S) are subject to facile rearrangements. 

Although the homoallylic- cyclopropylcarbinyl cyclization is well-precedented in carbonium ion chemistry (101, 102) there seem to be no reports of the direct cyclization of the tertiary 4-terpinenyl carbonium ion. However, deamination of cyclohex-3-enyl amine and solvolysis cyclo-hex-3-enyl tosylate gives exo- and n /o-bicyclo[3.1.0]hex-2-yl derivatives as 6—43% of the products resulting from nucleophilic capture (101, 103, 104). The modest yield of bicyclic products in these reactions apparently is the result of competing nucleophilic capture prior to cyclization and hydride shift to the 2-cyclohexenyl cation. More efficient cyclization occurs in the acetolysis of 2-bicyclo[2.2.2]oct-5-enyl tosylate (49) owing to the rigid boat-like conformation of the precursor (105). The high efficiency of the base-catalyzed cyclization of the epoxide of 4-iso-... 

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